Non-Newtonian effects on lubricant thin-film flows

Abstract

A long-standing question is readdressed as to whether the viscoelasticity can have a measurable effect on lubrication characteristics in thin-film flows. Specifically, a perturbation method based on the upper convected Maxwell constitutive equation is employed to analyze thin-film flows of a non-Newtonian fluid between two surfaces. The results show that there is a significant enhancement on the pressure field in the presence of viscoelasticity when the minimum thin-film thickness is sufficiently small. This mechanism suggests that viscoelasticity does indeed produce a beneficial effect on lubrication characteristics, which is consistent with experimental observations.

Keywords

lubrication / thin-film / non-Newtonian fluids / viscoelasticity